This invention relates generally to the field of child resistant closures for relatively small containers used to store medicinals and other contents potentially harmful if eaten by children of tender years. Devices of this general type are well known in the art, and the invention in specific constructional details which enable the opening of the closure by arthritic or other physically handicapped persons.
In the typical child proof container construction, it is known to provide a neck on the container wherein a tapered bead surrounds the mouth. The bead is interrupted over a relatively small arc. Disposed beneath the bead in spaced relation is a radially extending flange having an index mark. The closure includes an end wall and a peripheral side wall, the inner surface of which has one or more inwardly directed flanges which cooperate with the bead on the container mouth to maintain the closure in position. An additional small flange is configured to pass through the interrupted part of the bead, and an index mark is positioned on the outer surface of the side wall at that location. The container is opened by first rotating the closure relative to the container to align the index marks, and subsequently pushing upwardly on the closure in the area of the index mark to resiliently distort the closures sufficient to disengage it from the container. This opening procedure will normally be beyond the abilities of small children, and will frustrate their attempts to open the container while normal adults will have little difficulty. Unfortunately, such containers are often used by the elderly, many of whom have substantial physical disabilities by reason of arthritis, reduced muscular ability and the like. Such adults often have difficulty in gripping the closure to rotate it to the opening position, and once that is achieved, they have further difficulty in prying the closure in an upward direction to dislodge it from the mouth of the container.
The problem has been appreciated in the prior art. A typical attempt at resolution is found in the disclosure of U.S. Pat. No. 5,213,225 granted May 25, 1993 to Roger M. King, et al. The disclosed construction features an upwardly extending flange projecting from the upper surface of the end wall of the closure and extending across a diameter. The flange is provided with a transverse opening for the insertion of a tool, typically a pencil, to provide additional leverage. This construction does facilitate rotation of the closure relative to the container, particularly if a tool is used. However, it does not materially assist an arthritic user in the prying step which follows the alignment step. The flange is of planar configuration and relatively thin, so that it bends easily. It is also not positioned to enable the transmission of the necessary prying force. Most importantly, the flange must be manually engaged between the thumb and forefinger, a manipulation requiring a substantial pinching force of a degree unavailable to many persons.